WO 2011/033415 A1 discloses an illumination device comprising a power input stage, a power buffer stage, a driver and a light emitting diode circuit. The power input stage, the power buffer stage and the driver could be considered to form a power converter.
When replacing a halogen lamp by a light emitting diode circuit while keeping the halogen transformer, problems may occur with the halogen transformer, owing to the fact that the halogen transformer is designed to provide a first amount of power to the halogen lamp, which first amount of power will usually be larger than a second amount of power that is consumed by the light emitting diode circuit. Halogen transformers require a minimum output power to perform well, and light emitting diode circuits require for example three to ten times less power than halogen lamps to produce a similar amount of light.